Intraoperative Flow Research Articles

Intraoperative Flow Study Predicted the Postoperative Pulmonary Artery Pressure in the Bidirectional Glenn Operation.

The aim of this study was to evaluate the predictability of postoperative pulmonary artery pressure (PAP) using intraoperative flow study in patients undergoing bidirectional Glenn operation. Patients who underwent Glenn operation under cardiopulmonary bypass (CPB) were included in the study. During the operation, after the completion of additional procedures under CPB, an intraoperative flow study was performed prior to Glenn anastomosis. After the completion of bidirectional Glenn, the patient was separated from the CPB and PAP was measured. The relationship between this pressure and flow study measurement was analyzed. Nine patients who underwent bidirectional Glenn operation with additional procedures under CPB between July 2018 and January 2019 were included in the study. The median PAP was 9 mm Hg (interquartile range [IQR]: 7-10 mm Hg) in the flow study and 10 mm Hg (IQR: 8-11 mm Hg) after CPB, and the median difference between these pressures was 1 mm Hg (IQR: 1-3 mm Hg). There was a strong correlation between these two measurements (r = 0.732; P = .025). The results of this study show that PAP after the Glenn procedure can be estimated using an intraoperative flow study. We believe that this method may be useful in intraoperative decision-making for Glenn operation in single ventricular patients who require extensive pulmonary artery (PA) reconstruction due to limited PA development, branch PA stenosis, or nonconfluent PAs. Also, this method can be used as a sort of intraoperative pulmonary resistance reversibility study in patients with high preoperative pulmonary vascular resistance due to surgically correctable pulmonary venous hypertension.

Determinants of successful arteriovenous fistulae creation including intraoperative transit time flow measurement.

The prevalence of hemodialysis patients is increasing, and it is important to create the arteriovenous fistula as early as possible to avoid hemodialysis by central venous catheter. International guidelines recommend arteriovenous fistula as the vascular access of first choice. Arteriovenous fistulae are associated with a failure rate of 23%. The success of an arteriovenous fistula can be evaluated intraoperatively by physical examination and by measuring the blood flow. The aim of the study is to describe the predictive value of various factors for fistula maturation in the context to the current literature. We report on a prospective cohort study of 41 patients, undergoing a primary arteriovenous fistula at the upper extremity. The primary endpoint of the study was the successful fistula maturation after 6 weeks. The intraoperative measurement of the blood flow in the outflow vein has been identified as the unique significant parameter for the fistula maturation. The predictive value of intraoperative flow measurement is superior to intraoperative physical examination and could help reduce the fistula dysmaturation rate. Intraoperative transit time flow measurement is an easy method and can be used to predict successful fistula maturation in a high percentage rate.

Stable Hemodynamics within "No-Touch" Saphenous Vein Graft.

Purpose: To investigate the hemodynamics characteristics of the “no-touch” saphenous vein graft (SVG) conduits by nicardipine intraluminal administration in vivo experiment.Methods: A total of 59 consecutive patients were enrolled and underwent a sequential SVG to three non-left anterior descending (LAD) targets with the average runoff ≤2 mm, 30 with “no-touch” harvest technique (group A) and 29 with conventional preparation (group B). The patients were subject to nicardipine intraluminal injection during off-pump coronary artery bypass grafting (CABG) procedure. The intraoperative flow was measured with the ultrasonic transit time flow meter (TTFM), and the graft patency testified by multi-detector computed tomography (MDCT) angiography, respectively.Results: The baseline blood flow was higher in group A than that in group B (p <0.05). However, the increases in blood flow of SVG conduits in group A were lower than those in group B with 19.7 ± 5.9 vs. 35.4 ± 9.2 mL/min, 14.8 ± 5.6 vs. 23.1 ± 6.8 mL/min, 6.6 ± 2.1 vs. 11.2 ± 4.3 mL/min before the first, second, and third anastomose after nicardipine intraluminal administration, respectively (all p <0.01).Conclusions: No-touch SVGs were associated with higher baseline blood flow and less rises after nicardipine intraluminal administration during off-pump CABG procedure compared with conventional preparation. The no-touch SVGs seemed to be less spastic and well-tolerated on flow dilatation.

A successful intraoperative diagnosis of coexisting lymphoma and endometrial cancer

BackgroundThe coexistence of hematological malignancy with endometrial cancer is a rare phenomenon. We report a case of coexistence of endometrial cancer with follicular lymphoma which we suspected preoperatively and diagnosed during surgery by a multidisciplinary intraoperative assessment.Case presentationA 67-year-old woman was referred to our hospital due to a suspicion of an endometrial cancer. Endometrial biopsy revealed grade 1 endometrioid adenocarcinoma. MRI showed invasion of the tumor into the outer half of the myometrium, and abdominal CT showed para-aortic and atypical mesentery lymphadenopathy which was suspected to be metastasis of endometrial cancer or malignant lymphoma. Abdominal hysterectomy with bilateral salpingo-oophorectomy, pelvic and para-aortic lymphadenectomy, partial omentectomy, and mesentery lymph node biopsy for endometrial cancer were performed. The mesentery and para-aortic lymph nodes that were sent for frozen section analysis showed no metastasis of the endometrial cancer. We simultaneously conducted an unusual intraoperative emergent four-color flow cytometry and intraoperatively diagnosed a B cell lymphoma in the mesenteric lymph nodes. Because this multidisciplinary assessment, we were able to avoid an unnecessary intestinal resection. The final pathological diagnosis was an endometrioid carcinoma (G1, FIGO stage IA), with a synchronous follicular lymphoma.ConclusionAlthough a rare event in endometrial cancer surgery, it is necessary to be alert to the possibility of a synchronous lymphoma in cases of unusual site adenopathy.

Single Vessel Double Anastomosis for Flow Augmentation - A Novel Technique for Direct Extracranial to Intracranial Bypass Surgery.

A double anastomosis using a single superficial temporal artery (STA) donor branch for both a proximal side-to-side (S2S) and a distal end-to-side anastomosis is a novel direct bypass technique for use in selected patients necessitating flow augmentation. To describe the single-vessel double anastomosis (SVDA) technique, including its indications, advantages, and limitations, in addition to reporting our cases series of patients who underwent a SVDA bypass surgery. Patients undergoing a SVDA bypass at a single institution between January 2010 and February 2016 were retrospectively reviewed. Intraoperative flow data was collected, including STA cut-flow, bypass flows, and cut flow index (CFI). Bypass patency was assessed by cerebral angiography and quantitative magnetic resonance angiography with noninvasive optimal vessel analysis. Adverse events occurring during the hospital stay and clinical status at last follow up was recorded. Seven patients underwent SVDA bypass. Mean follow-up was 14.5 mo. Initial CFI for the S2S bypasses averaged 0.56±0.25 and CFI after the SVDA averaged 1.15±0.24. There was a statistically significant average difference in CFI before and after the SVDA bypass (p<.013). Thirteen bypasses (93%) were patent postoperatively, and remained patent at last follow up. Four patients experienced various postoperative complications. None of the patients had a new stroke since hospital discharge. SVDA is a novel technique that can be advantageous for selected cases of extracranial-to-intracranial bypass. Expertise in bypass procedures is a necessary prerequisite. Graft patency rates and complications appear comparable to other bypass techniques.

Perfusion Methods and Modifications to the Cardiopulmonary Bypass Circuit for Midline Unifocalization Procedures

Pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries (PA/VSD/MAPCAs) is a rare form of congenital heart disease. The midline unifocalization procedure has been developed for the treatment of PA/VSD/MAPCAs. These are complex and very lengthy procedures that require an entirely different method of perfusion. The purpose of this study was to review our perfusion modifications to support these unifocalization procedures. Sixty-four unifocalization procedures have been performed at our institution during the past 3 years. The median age was 4.1 months (range 1 month–3.5 years) and the median weight at surgery was 4.5 kg (range 3.5–19 kg). The median duration of cardiopulmonary bypass was 352 minutes (range 128–629 minutes), and the median duration of cross-clamp was 24 minutes (range 14–72 minutes). The conduct of surgery included cooling to a rectal perfusion temperature of 25° and a flow rate of 100 mL/kg/min. A pH-stat strategy and del Nido cardioplegia were used. Modifications to the cardiopulmonary bypass circuit include upsizing the oxygenator, reservoir, cannulae, vent catheter, and tubing. All circuits were modified to include the capability of performing an intraoperative flow study. This study is used to determine whether the VSD can be closed during surgery. A collateral flow study circuit is also set up for first-time operations to measure the residual collateral flow after all of the MAPCAs have been harvested. Patients who require midline unifocalization will invariably require very lengthy periods of support on cardiopulmonary bypass. We have adapted our perfusion circuitry to prepare for the demands on the bypass circuit to meet the requirements of this patient population. Our institution has developed a systematic approach for the conduct of perfusion to best serve our patients presenting with PA/VSD/MAPCAs.

Application of Intraoperative FLOW 800 Indocyanine Green Videoangiography Color-Coded Maps for Microsurgical Clipping of Intracranial Aneurysms

Indocyanine green (ICG) videoangiography (VAG) is an established method for assessment of cerebral blood flow during microsurgical clipping of intracranial aneurysms. FLOW 800 is a surgical microscope-integrated software program that shows the cerebral blood flow in color-coded maps, thus providing semi-quantitative and real-time analysis of ICG data. We aimed to establish reference values for FLOW 800 parameters before and after microsurgical clipping of intracranial aneurysms and to evaluate the potential of FLOW 800 to guide intraoperative decisions. We retrospectively reviewed 54 patients (mean age, 53.6 ± 11.6 years) who underwent microsurgical clipping for 60 aneurysms and intraoperative evaluation of ICG fluorescence dynamics using FLOW 800 color-coded maps. FLOW 800 data were correlated with patient characteristics, clinical outcomes, and intraoperative decision making. There were no significant differences in FLOW 800 data between ruptured and unruptured aneurysms (P>0.05). Likewise, the hemodynamic parameters were not significantly different before and after definite clip placement (P > 0.05). However, in 2 cases, analysis of transit times by FLOW 800 analysis showed a hemodynamically significant clip stenosis that might have been missed by conventional ICG-VAG and resulted in adjustment of the clip position. Overall, there was 1 cerebral infarction, which was not related to clip placement. FLOW 800 is a useful adjunct to ICG-VAG for intraoperative assessment of cerebral perfusion and may help to identify hemodynamically relevant clip stenosis. The beneficial impact of FLOW 800 on clinical outcome after microsurgical clipping needs to be confirmed by comparative studies.

Universal fluorescence module for intraoperative fluorescein angiography-a technical report.

Even in specialized centers, suboptimal aneurysm clipping can be as high as 12%. Intraoperative fluorescence angiography with indocyanine green and, more recently, fluorescein sodium have been shown to be a good method for intraoperative flow assessment. However, the cost with the apparatus it entails limits its widespread use. We have developed a low-cost universal fluorescence module (FM) designed to visualize fluorescein and perform intraoperative angiography. The purpose of this paper is to describe this device as well as to present our early experience with its use in the treatment of cerebral aneurysms. A FM was designed and built using a cyan-blue narrow bandpass (460 to 490nm) excitation filter and a yellow-orange longpass (blocking wavelengths under 520nm) barrier filter mounted on a 3D-printed holding tray in a specific disposition to perfectly match the light source and the objective lens of the surgical microscope. It allowed switching from white light to fluorescence mode in a simple and sterile fashion. Its perfect attachment to the microscope was possible by reusing the lens fittings extracted from used original drape sets that would otherwise be discarded. Four patients underwent aneurysm clipping using the FM at two institutions from April to September 2018. A bright green fluorescence against a dark background was observed after intravenous bolus of fluorescein. Blood vessels became obviously distinct from non-contrast-filled structures such as clipped aneurysms and the brain. Vascular anatomy could be appreciated without any distortion, including perforating arteries. Intraoperative fluorescence angiography was successfully performed with the use of this universal FM after intravenous injection of fluorescein sodium. This simple and low-cost device may be useful in resource-limited centers, where other sorts of intraoperative angiography are not available.

Early silent graft failure in off-pump coronary artery bypass grafting: a computed tomography analysis†.

The purpose was to assess predictors of early silent graft failure prior to discharge by multislice computed tomography in patients after off-pump coronary artery bypass grafting. From January 2017 until April 2018, 192 computed tomographic scans of consecutive asymptomatic patients were performed (seventh postoperative day ± 4 days) and analysed retrospectively. In total, 359 arterial and 278 venous anastomoses were evaluated. Two patient groups (overall patent anastomoses versus at least 1 occluded anastomosis) were compared. Cardiovascular risk factors, collateralization according to Rentrop, grade of native vessel stenosis and intraoperative flow measurements were analysed. Inferential statistics were performed with the Mann-Whitney U-test. Nominal and categorical variables were tested with the Fisher-Freeman-Halton exact test. In 33 patients, at least 1 occluded anastomosis could be identified, predominantly in women (P = 0.04). The patency of the arterial anastomoses was 96.4% and 88.9% for the venous anastomoses. In 14 patients with occluded anastomoses, a successful interventional revascularization was performed before discharge. There were significant differences in lower bypass flow [P = 0.02, odds ratio 3.2, 95% confidence interval (CI) 1.7-6.0] and higher pulsatility index (P < 0.001, odds ratio 4.5, 95% CI 2.4-8.5) in the occluded group. A calculated cut-off value identified an increased probability for graft occlusion at a flow under 23 ml/min and a pulsatility index greater than 2.3. Early silent graft failure occurred predominantly in venous grafts, with a tendency to female gender. A lower flow rate and a higher pulsatility index were significantly associated with graft occlusion, whereas collateralization and the degree of native vessel stenosis seem to play a tangential role. Fourteen patients had a successful percutaneous revascularization before discharge. NCT03657199.

Malignancy Index Using Intraoperative Flow Cytometry is a Valuable Prognostic Factor for Glioblastoma Treated With Radiotherapy and Concomitant Temozolomide.

Intraoperative prediction of radiochemosensitivity is desirable for improving the clinical management of glioblastoma (GBM) patients. We have previously developed an original technique for intraoperative flow cytometry (iFC) and defined a malignancy index (MI). To determine whether MI correlates with prognosis in GBM patients who underwent the standard treatment protocol of radiotherapy and temozolomide administration. The current study included 102 patients with GBM that had been newly diagnosed from 2010 to 2015 who underwent our iFC analysis and received the standard treatment protocol. We evaluated MI values in each patient, then statistically analyzed the relationship between MI and prognosis using survival analysis that include other clinicopathological factors (age, sex, Karnofsky performance status [KPS], extent of resection, second-line bevacizumab, O6-methylguanine-DNA methyltransferase [MGMT] status, MIB-1 labeling index, and mutation of the isocitrate dehydrogenase 1 gene [IDH1]). Log-rank test revealed that age, KPS, extent of resection, MGMT status, IDH1 mutation, and high MI (≥26.3%) significantly correlated with overall survival. Multivariate analysis with Cox regression modeling identified MI as the most significant prognostic factor (hazard ratio = 2.246; 95% confidence interval = 1.347-3.800; P = .0019). MI showed strong correlation with IDH1 mutation status in chi-square test (P = .0023). In addition, log-rank test revealed that MI affects overall survival more strongly in patients with IDH1 wildtype than those with IDH1 mutant. MI from an iFC study may help predict the prognosis in patients with GBM who receive the standard treatment. Survival can be related to sensitivity to radio-chemotherapy.

Outcomes After Initial Unifocalization to a Shunt in Complex Tetralogy of Fallot With MAPCAs

Our approach to tetralogy of Fallot (TOF) with pulmonary atresia and major aortopulmonary collateral arteries (MAPCAs) emphasizes early single-stage unifocalization and intracardiac repair. However, a subset of patients with small native pulmonary arteries (PAs) and MAPCAs undergo unifocalization to a shunt rather than simultaneous intracardiac repair. Patients with TOF/MAPCAs who underwent complete unifocalization to a systemic-to-PA shunt by a single surgeon were reviewed. The decision to perform simultaneous intracardiac repair was based on an intraoperative flow study or empirical assessment of PA and MAPCA size. From November 2001 to December 2017, 57 patients with TOF/MAPCAs underwent unifocalization to a shunt at a median age of 6.9 months. Genetic abnormalities were documented in 60% of patients, including a chromosome 22q11 deletion in 25 and Alagille syndrome in 8. Twenty patients (35%) had undergone prior surgery elsewhere (n= 16) and/or at our center (n= 7). During a median follow-up of 5.4 years, 9 patients had additional surgery to revise the PA reconstruction before complete repair, and 38 patients underwent complete repair. Five years after unifocalization, survival was 74% ± 6%. At follow-up, the median PA to aortic systolic pressure ratio was 0.36 and was greater than 0.50 in 2 patients. In patients with the smallest MAPCAs and PAs, single-stage unifocalization to a shunt followed by intracardiac repair yields an excellent outcome in most cases.

Caliber-targeted reinterventional overdilation of iliac vein Wallstents

BackgroundWallstents (Boston Scientific, Marlborough, Mass) are most commonly used in iliac-caval stenting. Approximately 20% of stented limbs require reintervention to correct in-stent restenosis (ISR) or stent compression (SC). Corrective balloon dilation to rated stent caliber (isodilation) is not always successful. We investigated whether modest overdilation of the Wallstent by 2 to 4 mm (10%-20%) beyond the rated diameter would yield better mechanical clearance of ISR/SC, leading to a larger flow channel, improved conductance, reduction of peripheral venous pressure, and better clinical outcome. Outflow lumen caliber exponentially influences peripheral venous pressure, a key mechanism in chronic venous disease. Beyond the mechanical effects, the rationale for overdilation rests on the theory that an improvement in flow channel at the margins may yield an outsized pressure reduction and clinical improvement. MethodsThere were 274 previously stented limbs that underwent reinterventional balloon dilation for clearance of ISR/SC during a recent 3-year period. Isodilation to rated diameter of the stent was judged effective in 71 limbs (isodilated subset); 203 limbs (overdilated subset) for which initial isodilation was ineffective underwent overdilation of the resident Wallstent by 2 to 4 mm (10%-20%) beyond the original rated diameter. IVUS planimetry was used intraoperatively to calculate SC and ISR and their subsequent clearance in the two subsets. The dilated segments were observed by clinical and duplex ultrasound examination afterward. The two subsets were compared in the following outcome measures: intraprocedural efficacy in clearing ISR/SC and achieving target lumen caliber, subsequent clinical outcomes, duplex ultrasound caliber durability, and improvement in supine foot venous pressures. This is a single-center retrospective analysis of data contemporaneously entered into a time stamped electronic medical record system. ResultsThe median follow-up was 18 months (range, 1-35 months). Overdilation of the stent resulted in significantly better intraoperative flow channel area improvement per intravascular ultrasound. This was reflected in significantly better clinical outcome and improvement in peripheral venous pressure in the overdilated subset. Overdilation appeared to be durable up to 20 months after intervention by duplex ultrasound monitoring. ConclusionsOverdilation appears to be a useful technique to correct ISR/SC and to restore target lumen caliber during reinterventional correction of a resident iliac vein Wallstent. More durable caliber improvement, superior clinical outcome, and reduction in peripheral venous hypertension were noticed in overdilated stents compared with isodilation.

Intraoperative flow profiles of arterial and venous bypass grafts to the left coronary territory.

The different mechanical and vasodilatory properties of arteries and veins may influence their flow profiles when used for coronary artery bypass grafting (CABG). This may be of significance when assessing the cut-off values for adequate flow. However, conduit-related flow differences are less examined. In a study of 268 patients, transit time flowmetry parameters of 336 arterial and 170 venous conduits all grafted to the left coronary territory were compared. With transit time flowmetry, the mean graft flow (MGF), pulsatility index, percentage of diastolic filling and percentage of backwards flow were measured. Conduit-related differences were further compared according to on- or off-pump CABG (ONCABG versus OPCABG) surgery. Overall MGF and pulsatility index were comparable between arterial and venous grafts, but in arterial grafts, MGF was higher during ONCABG than during OPCABG (49.1 ± 35.3 ml/min vs 38.8 ± 26.6 ml/min; P = 0.003). Percentage of diastolic filling was higher in arterial grafts than in venous grafts (overall 71.0 ± 7.9% vs 63.7 ± 11.1%; ONCABG 69.9 ± 7.1% vs 63.9 ± 10.4%; OPCABG 71.9 ± 8.3% vs 63.4 ± 12.2%; all P < 0.001). Furthermore, percentage of backwards flow was higher in arterial grafts than in venous grafts in the overall (2.3 ± 3.2% vs 1.7 ± 3.2%, P = 0.002) and in the ONCABG (2.3 ± 3.2% vs 1.3 ± 2.5%, P < 0.001) cohorts. In venous grafts, percentage of backwards flow was lower during ONCABG versus OPCABG (1.3 ± 2.5% vs 2.6 ± 3.9%, P = 0.016). No statistically significant difference was observed for MGF and pulsatility index between arterial and venous conduits. However, arterial grafts have significantly higher diastolic filling and backwards flow than venous grafts. Furthermore, arterial grafts have a significantly higher MGF in ONCABG versus OPCABG.

A comparative study of intraoperative frozen section and alpha defensin lateral flow test in the diagnosis of periprosthetic joint infection

Background and purpose — For decision-making (aseptic vs. septic), surgeons rely on intraoperatively available tests when a periprosthetic joint infection (PJI) cannot be confirmed or excluded preoperatively. We compared and evaluated the intraoperative performances of the frozen section and the alpha defensin lateral flow test in the diagnosis of PJI.Patients and methods — In this prospective study, consecutive patients with indicated revision surgery after arthroplasty were included. Patients were classified as having PJI using the MusculoSkeletal Infection criteria. The presence of alpha defensin was determined using the lateral flow test intraoperatively. During revision surgery, tissue samples were harvested for frozen and permanent section. Analysis of diagnostic accuracy was based on receiver-operating characteristics.Results — 101 patients (53 hips, 48 knees) were eligible for inclusion. Postoperatively, 29/101 patients were diagnosed with PJI, of which 8/29 cases were definitely classified as septic preoperatively. Of the remainder 21 septic cases, the intraoperative alpha defensin test and frozen section were positive in 13 and 17 patients, respectively. Sensitivities of the alpha defensin test and frozen section were 69% and 86%, respectively. The area under the curves of both tests showed a statistically significant difference (p = 0.006).Interpretation — The frozen section showed a significantly higher performance compared with the alpha defensin test and a near perfect concordance with the definitive histology, and therefore remains an appropriate intraoperative screening test in diagnosing PJI. Although the sensitivity of the alpha defensin test was lower compared with that of frozen section, this test is highly specific for confirming the diagnosis of PJI.

Intraoperative Flow Cytometry for Diagnosis of Central Nervous System Lesions.

Intraoperative Flow Cytometry for Diagnosis of Central Nervous System Lesions.

Intraoperative Flow Cytometry for Diagnosis of Central Nervous System Lesions.

Intraoperative Flow Cytometry for Diagnosis of Central Nervous System Lesions.

Donor Risk Index Has an Impact in Intraoperative Measure of Hepatic Artery Flow and in Clearance of Indocyanine Green: An Observational Cohort Study

BackgroundThe increase in indications for liver transplantation has led to acceptance of donors with expanded criteria. The donor risk index (DRI) was validated with the aim of being a predictive model of graft survival based on donor characteristics. Intraoperative arterial hepatic flow and indocyanine green clearance (plasma clearance rate of indocyanine green [ICG-PDR]) are easily measurable variables in the intraoperative period that may be influenced by graft quality. Our aim was to analyze the influence of DRI on intraoperative liver hemodynamic alterations and on intraoperative dynamic liver function testing (ICG-PDR). MethodsThis investigation was an observational study of a single-center cohort (n = 228) with prospective data collection and retrospective data analysis. Measurement of intraoperative flow was made with a VeriQ flowmeter based on measurement of transit time (MFTT). The ICG-PDR was obtained from all patients with a LiMON monitor (Pulsion Medical Systems AG, Munich, Germany). DRI was calculated using a previously validated formula. Normally distributed variables were compared using Student's t test. Otherwise, the Mann-Whitney U test or Kruskal-Wallis test was applied, depending on whether there were 2 or more comparable groups. The qualitative variables and risk measurements were analyzed using the chi-square test. P < .05 was considered statistically significant. ResultsDRI score (mean ± SD) was 1.58 ± 0.31. The group with DRI >1.7 (poor quality) had an intraoperative arterial flow of 234.2 ± 121.35 mL/min compared with the group having DRI < 1.7 (high quality), with an intraoperative arterial flow of 287.24 ± 156.84 mL/min (P = .02). The group with DRI >1.70 had an ICG-PDR of 14.75 ± 6.52%/min at 60 minutes after reperfusion compared to the group with DRI <1.70, with an ICG-PDR of 16.68 ± 6.47%/min at 60 minutes after reperfusion (P = .09). ConclusionPoor quality grafts have greater susceptibility to ischemia-reperfusion damage. Decreased intraoperative hepatic arterial flow may represent an increase in intrahepatic resistance early in the intraoperative period.

Midline one-stage complete unifocalization early outcomes from a single center.

Objective:This study aims to present our experience with single-stage complete unifocalization and intraoperative flow study for the repair of ventricular septal defect, pulmonary atresia, and major aortopulmonary collateral arteries.Methods:This study was conducted through retrospective chart review of all the patients who underwent complete single-stage midline unifocalization in a single tertiary-care institution.Results:Twenty-two patients underwent midline single-stage unifocalization. The median age was 11 months (IQR: 5–21 months). The number of collateral arteries unifocalized was between one and three (median two). In-hospital mortality was 5%. Follow-up was complete; and the median follow-up regarding survival was 20 months (IQR: 10–28 months). There were three late deaths, and the estimated survival rate was 80% at 10 months and on. Out of 22 patients, ventricular septal defect was closed in the first surgery in three patients (14%) and the second surgery in four patients (19%). Total seven patients underwent surgical total repair (32%). Additionally, one out of four patients whose ventricular septal defects were closed with a fenestrated patch is under follow-up with a small ventricular septal defect, while two are waiting for ventricular septal defect closure. Therefore, total eight patients (36%) have reached total correction.Conclusion:Single-stage unifocalization is a feasible treatment option in ventricular septal defect, pulmonary atresia, and major aortopulmonary collateral arteries. This cohort had unfavorable results regarding the rate of complete repair. The pitfalls encountered were related to problems with meticulous surgical technique, complete unifocalization, and correct implementation of the flow study.

Correlates of haemodynamic flow characteristics of sequential saphenous vein grafts in coronary artery bypass grafting.

A sequential bypass technique has been widely used in the saphenous vein grafts (SVGs) during coronary artery bypass grafting (CABG) surgery. The aim of the present study was to investigate the correlates of haemodynamic flow characteristics of sequential SVGs using transit-time flow measurement. From January 2013 to December 2016, 235 patients underwent isolated CABG using 1 aortosequential SVG to non-left anterior descending targets and the left internal mammary artery to the left anterior descending coronary artery. Among them, 212 patients have completed computed tomography angiography at 1-year follow-up and were included in the present study. The intraoperative flow rate and pulsatility index (PI) of sequential SVGs were assessed with transit-time flow measurement. The univariable and multivariable stepwise linear regression analyses of the possible correlating variables, including distal-end coronary artery (DECA) characteristics, were performed. For sequential SVGs, the mean proximal flow rate was 45.8 ± 19.2 ml/min, and the mean PI was 3.17 ± 1.00. We assessed the following correlates for proximal flow rate and PI: patient characteristics and DECA characteristics. Independent correlates of proximal flow rate were triple sequential SVG (by 21.0 ± 2.5 ml/min; P < 0.001), the DECA with more severe proximal stenosis (3.6 ± 1.3 ml/min per 10% increase; P = 0.007) and the DECA with larger diameter (≥1.5 mm) (by 4.8 ± 2.3 ml/min; P = 0.038). For PI, independent correlate was triple sequential SVG (by -0.55 ± 0.15; P < 0.001), and the DECA with larger diameter (≥1.5 mm) showed a strong trend (P = 0.069). The flow rate plotted against the logarithmic transformation of PI showed a significant inverse relationship in the linear regression analysis (P < 0.001). At 1-year follow-up, the patency of the proximal segment (between the aorta and the first side-to-side anastomosis) was 99.5% (211 of 212). Triple sequential SVG, the DECA with a larger diameter and more severe proximal stenosis were associated with higher proximal flow rate, whereas triple sequential SVG was associated with lower PI. These findings provide new data on flow characteristics and may guide subsequent studies towards improving sequential SVG patency.

Endoscope- versus microscope-integrated near-infrared indocyanine green videoangiography in aneurysm surgery.

The quality of surgical treatment of intracranial aneurysms is determined by complete aneurysm occlusion while preserving blood flow in the parent, branching, and perforating arteries. For a few years, there has been a nearly noninvasive and cost-effective technique for intraoperative flow evaluation: microscope-integrated indocyanine green videoangiography (mICG-VA). This method allows for real-time information about blood flow in the aneurysm and the involved vessels, but its limitations are seen in the evaluation of structures located in the depth of the surgical field, especially through small craniotomies. To compensate for these drawbacks, an endoscope-integrated ICG-VA (eICG-VA) was developed. The objective of the present study was to assess the use of eICG-VA in comparison with mICG-VA for intraoperative blood flow evaluation. In the period between January 2011 and January 2015, 216 patients with a total of 248 intracranial saccular aneurysms were surgically treated in the Department of Neurosurgery of Saarland University Medical Center in Homburg/Saar, Germany. During 95 surgeries in 88 patients with a total of 108 aneurysms, intraoperative evaluation was performed with both eICG-VA and mICG-VA. After clipping, evaluation of complete aneurysm occlusion and flow in the parent, branching, and perforating arteries was performed using both methods. Intraoperative applicability of each technique was compared with the other and with postoperative digital subtraction angiography as a standard evaluation technique. Evaluation of completeness of aneurysm occlusion and of flow in the parent, branching, and perforating arteries was more successful with eICG-VA than with mICG-VA, especially for aneurysm neck assessment (88.9% vs 69.4%). For 63.9% of the aneurysms (n = 69), both methods were equivalent, but in 30.6% of the cases (n = 33), the eICG-VA provided better results for evaluating the post-clipping situation. In 4.6% of these aneurysms (n = 5), the information given by the additional endoscope considerably changed the surgical procedure. Thus, one residual aneurysm (0.9%), two neck remnants (1.9%), and two branch occlusions (1.9%) could be prevented. Nevertheless, two incomplete aneurysm occlusions (1.9%) and six neck remnants (5.6%) were revealed by postoperative digital subtraction angiography. Endoscope-integrated ICG-VA seems to be an improvement that might increase the quality of aneurysm surgery by providing additional information. It offers higher illumination, magnification, and an extended viewing angle. Its main advantage is its ability to assess deep-seated aneurysms, especially through small craniotomies, but further studies are required.